1. Field of the Invention
The present invention generally relates to a printing press, wherein such a printing press may include a device for uniformly sucking a plane body provided on a support. The device comprises a closed suction chamber, the supporting surface of which features suction ports, and a blower which is assigned to the suction chamber and produces an underpressure, or vacuum pressure, in the suction chamber.
Additionally, the present invention relates to a device for uniformly sucking a plane body provided on a support, especially for printing machines and their accessories, the device comprising a closed suction chamber, the supporting surface of which features suction ports, and a blower which is assigned to the suction chamber and produces an underpressure, or vacuum pressure in the suction chamber.
2. Summary of the Invention
Such a device may be used on a measuring table, or aligning table, for example, when providing a suction force on sheets. It may also be used on transport drums on the respective outer cylindrical surface of which, for example, printed paper sheets have a suction force applied thereto in order to be conveyed to a new processing station.
Known devices for providing a suction force on plane bodies that are provided on a respective support have the disadvantage that, in the marginal area of the body to be sucked, the vacuum pressure or underpressure of the suction air can drop considerably so that it cannot always be ensured that the marginal areas come to lie properly on the supporting surface of the device. Attempts have been made to avoid this phenomenon by increasing the suction capacity of the blower used and thus the underpressure within the suction chamber. As a result thereof, the production costs as well as the operating costs are also increased without ensuring that the plane and format-independent bodies, featuring a certain stiffness, such as printing plates, come to lie properly on a support, especially in view of the marginal areas.
Other systems solve this problem by increasing the energy or air consumption, or by switching the vacuum zones depending on the respective format used. The systems using vacuum zones tend to comprise an expensive vacuum pump which does not allow any leaking, as such leakage losses would cause the vacuum to collapse. Furthermore, such systems tend not to be very dynamic with respect to their suction behavior.